The aggregate productivity slowdown: A system approach
通过四种技术变革模型估计美国经济的资本劳动替代弹性和技术偏向，发现要素增强型技术变革增长率非恒定，劳动增强型增速放缓，资本增强型虽不可忽略但迅速消失。
I revisit the productivity slowdown debate by estimating the capital-labor elasticity and the bias of technical change for the U.S. economy under four different models of technical change. One with constant growth rates, one with a structural break in the constant growth rates, one in which growth is linear, and one with flexible time-varying growth rates. I find evidence in support of non-constant growth rates of factor-augmenting technical change. Labor-augmenting technical change growth rates are decelerating, while capital-augmenting technical change is non negligible but vanishes quickly.